/*
 * Project CHEN Rendering Engine : /material.hpp
 * Created: 2020-12-16, Last modified:  2021-02-22
 * 
 * This is the material header file.
 * 
 * Copyright (C) 2021 Hineven (hineven@pku.edu.cn)
 * 
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#ifndef _H_MATERIAL
#define _H_MATERIAL
#include "heads.hpp"
#include "interaction.hpp"
namespace chen {
class Material {
public:
    int flags;
    // Apply material effects to the surface interaction. Including 
    // setting the eta value and calculaing the scattering function
    // (BSDF / BSSRDF) of the hit point. _dir_ is the value deciding
    // the direction of light transport in bidirectional rendering
    // methods (camera / photon)
    const Texture<Normal> * bumpmap;
    inline Material (const Texture<Normal> * bumpmap): bumpmap(bumpmap) {}
    virtual bool apply (SurfInteract * si, bool dir) const = 0;
    inline void bump (SurfInteract * si) const {
        // TODO actualy bump the surfinteract
        si->ns = si->ng;
        si->nsy = si->ngy;
        
    }
};
}
#endif